In the four years that the Cooperative Family Registry for Breast Cancer Studies (CFRBCS) has been funded, the six sites have accrued the world's largest population of women and families at genetic risk to develop breast and ovarian cancer. Subjects have been recruited from both population-based and clinic-based sites in the U.S., Canada and Australia. Biospecimens and extensive data have been collected in a uniform fashion and systematic follow-up is ongoing. The Utah site of the CFRBCS (termed interchangeably by the Utah Family Registry or the High Risk Breast genes. The Utah Family Registry, along with a unified CFRBCS, is uniquely able to conduct research in the genetic epidemiology of breast cancer. The multi-center nature and centralized database allow us to study to study a large cohort rapidly. The collaborative relationships developed during the formation of the CFRBCS infrastructure have facilitated agreement about research methods and data collection, placing us in strong position to achieve our research goals in a timely and cost-effective manner. This application contains four separate sections. First, we describe the progress of the Utah Family Registry and our plan to enhance the value of the CFRBCS for research studies conducted both by the CFRBCS and by outside investigators. This will be accomplished by expanding the number of mutation-carrying subjects enrolled and by providing breast and ovarian epithelial cell lines from subjects with breast cancer predisposition genes. We also describe our plans to collaborate in research conducted by each of the other CFRBCS sites. The final overview and progress report of the CFRBCS and coordinated by the Utah Family Registry. These include a definitive study of the prognosis and pathologic characteristics of breast cancers occurring in women will germline mutations in BRCA1 and BRCA2 genes, and a study of the screening and prevention practices and efficacy in mutation carriers.